MECHANICAL PROPERTY OF FINE GRAINED CONCRETE WITH DIFFERENT CEMENTING MATERIAL AFTER EXPOSURE TO HIGH-TEMPERATURE

To improve the high temperature resistance of fine grained concrete for textile reinforced concrete matrices, 120 prism specimens (40mm×40mm×160mm) for flexural tests and 240 cube specimens (40mm×40mm×40mm) were prepared in this paper for compressive strength tests after exposure to high temperature. The effects of different cementing materials on mechanical properties of fine grained concrete were studied, including the effect of nanomaterial admixtures and the use of alumina cement as main cementing material. The results show that nanometer SiO₂ aerogel powder cannot improve the high temperature resistance of fine grained concrete when volume fraction is 1.5% or 3.0%. Nanosized ceramic powder with quality content of 5.0% can improve the residual compressive and flexural strength of fine grained concrete by 84.2% and 120.9%, respectively, over that of concrete without nanosized ceramic powder at 800℃. When T_R=800℃, mechanical properties of specimens with alumina cement as the main cementing material increase greatly compared with ordinary fine grained concrete specimens. Alumina cement concrete specimens with reactive powder mixed have higher relative residual compressive and flexural strength than those without reactive powder at 800℃.